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REPRINTED FROM AND COPYRIGHTED AS A PART OF JOURNAL AMERICAN WATER WORHs ASSOCIATION VOL 60, No. 10, October 1968 PdnW In U. S. A. Concrete Reservoir Design Russell C. Kennur A paper presented on Jun. 4, 1968, at the Annual Conference, Cleve- land, by Russell C. Kenmir (Active Member, AWWA), Pres. and Chief Engr., lames M. Montgomery, Cow, Engrs., Inc., Pasadena, Calif. RESERVOIRS involve a multitude of details which must be designed and constructed properly. The diffi- culties experienced with many reser- voirs have been due not so much to structural inadequacies, but rather to insufficient attention to seemingly mi- nor details, such as locations of con- struction joints, installation of water - stops, vibration and curing of concrete, and design and construction of under - drains. These details can cause costly maintenance problems if not properly designed and constructed. For this reason, this paper emphasizes such details. Common Types The elements of the most common types of concrete reservoirs are briefly as follows: The walls may be of nonprestressed design or prestressed or post -tensioned design. The nonprestressed design may have (1) a sloping wall or (2) a vertical wall of a circular -hoop -ten - Sion, cantilever, or vertical beam type. The prestressed or post -tensioned de- sign may be (1) cast or shot -in -place core -wall, wrapped with rods equipped with turnbuckles, (2) cast or shot -in - place core -wall, with embedded tubes or paper sheathing enclosing post -ten- sioning cables, (3) cast or shot -in -place core -wall, with or without embedded steel shell, and• wrapped with post - tensioned wire, or (4) precast, pre- stressed wall panels supported at top and bottom with ring girders. The roof of a cast -in -place design may be one of the following types: (1) multiple -arch, (2) multiple -dome, (3) single -dome, (4) beam, joint, and slab, or (5) flat -slab. The roof on a precast design may- be either a non - prestressed type or a pretensioned or post -tensioned type. Selection of Type The esthetic requirements of the site neighborhood and the relation of the site elevation to the desired maximum water surface elevation are important factors in selecting the type of reser- voir. Frequently a study is made to determine whether a circular, rectangu- lar, or irregularly shaped structure would fit the site best. A concrete reservoir with the roof and walls ex- posed to the weather is likely to require more maintenance than buried concrete reservoirs. Buried structures are not subject to wide temperature variations, wetting and drying conditions, and, in cold climates, to freezing and thawing conditions. With the excellent materials now available, the reservoir designer has 1181 RICHARD BRADY &ASSOCIATES, INC. F-50